## Tuesday, January 17, 2012

### Jennifer's Scribe Post

Here were today's notes:

Estimating Square Roots

First we have to find the perfect squares that tells us where the square root lies between.
-So what would be a perfect square that is before 18 and after 18?
-16 (4x4) and 25 (5x5)

Now we have to find where 18 would fit on this number line.
To find that we would have to find the midpoint in between so we put a line through the middle. We then decide if 18 is closer to 16 or 25. - You would then put 18 on the left side of the red line through the middle.
Now you have to estimate the number that has to be squared to get the square root of 18.
To find the whole number, you should
look at smaller square root that the number is in between, and that should be the whole number. - The square root before 18 is 16.
To find the decimal is where estimating is used. This is also where the line through the middle is used. -Now we know that it is less than the
midpoint, for sure the decimal has to

Now we end up with something like 4.2. be 0.2, 0.3 or 0.4.

There are 2 ways: the first one is making a whole number with a decimal and the second one is making the square root a mixed fraction.

Making a whole number with a decimal is good but still isn't the best.

You would take the perfect square and use
that to find the square root easier. You know that 28 is less than 36 but more than 25 so the whole number has to be 5. You also know that 28 is much closer to 25 than 36 so the decimal can be 0.2, 0.3, 0.4.

The second way is finding the square root as a mixed number.

1st step- Finding the whole number.
You know that 28 is less than 30 so the square root must be less than 6. So it
is 5.

2nd step
- Finding the numerator of the fraction
You have to count the how much it takes to get from the smaller perfect square to 28.
S0 28 is 3 after 25.

3rd step- Finding the denominator of the fraction
You have to subtract the bigger square root from the smaller square root.
Bigger square root- Smaller square root= Denominator
36-25= 11

This is the best way to find the square root of a non-perfect square root more accurately.

Here's a video that talks about estimating square roots.

Here's a link of a game to practice with perfect squares
http://www.quia.com/ba/79697.html

I hope this scribe post helps!!!
Please comment especially if I forgot something or if said something that is incorrect.